The term impostor phenomenon emerged in the late 1970s during the second wave of the feminist movement in the United States, and interest in the phenomenon has continued over the past four decades, with research examining the causes and effects of individuals’ self-doubt and impostor feelings. Within this growing body of literature, however, there was a gap related to understanding the impostor phenomenon over one’s lifespan. The purpose of this qualitative interview study was to explore the lived experiences of the impostor phenomenon in women over the age of 60 across their lifespans in order to gain a better understanding of their life transitions and the inner world of the impostor phenomenon. The following research question guided the study: How do women over the age of 60 reflect on a life in relationship to the impostor phenomenon? Using an interpretivist approach, the author explored how women made meaning of their experiences of self-doubt and impostorism over time. A total of 24 women participated in the study. The participants were White, middle-class, American women with different educational and professional histories. All participants completed the Clance Impostor Phenomenon Scale and a demographic profile; 11 women participated in semi-structured interviews. Women’s developmental theory served as a basis for identifying the factors that influenced participants’ self-doubt and impostor feelings. The addition of constructive-developmental theory provided a lens for exploring how these women internalized societal messages and the ways they balanced conflicting societal cues with their desires to “be more.” The incorporation of these two theoretical frameworks allowed for an understanding of the impostor phenomenon from the outside in. The findings suggest the existence of a polarity, with the participants managing both self-doubt and determination. Moreover, the ability to manage this polarity suggests a navigation of truces which supports adult development and growth. The findings can inform employers and educators on how to better support women who live with impostor feelings. Understanding how self-doubt and impostor feelings manifest over time also has the potential to offer insights into how women navigate in the modern world.